/*
 * Copyright:  2018 smarabbit studio.
 *
 *  Licensed under the Confluent Community License; you may not use this file
 *  except in compliance with the License.  You may obtain a copy of the License at
 *
 *  http://www.confluent.io/confluent-community-license
 *
 *  Unless required by applicable law or agreed to in writing, software
 *  distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 *  WARRANTIES OF ANY KIND, either express or implied.  See the License for the
 *  specific language governing permissions and limitations under the License.
 *
 *  @作   者： 黄开晖 (117227773@qq.com)
 *  @日   期:  2020年9月4日
 */

package com.massyframework.beanskin.runtime.framework.installing;

import java.util.Objects;

import javax.script.ScriptEngine;

import com.massyframework.beanskin.assembly.Assembly;
import com.massyframework.beanskin.service.ServiceRepository;

/**
 * {@link ExpressionFactory}, 创建{@link Expression}实例的工厂
 */
public class ExpressionFactory {
	
	private Assembly assembly;
	
	public ExpressionFactory(Assembly assembly) {
		this.assembly = Objects.requireNonNull(assembly, "\"assembly\" cannot be null.");
	}

    /**
     * 创建表达式
     * @param resultType {@link Class}, 表达式执行后返回的类型
     * @return {@link Expression}
     */
    public <T> Expression<T> createExpression(Class<T> resultType){
    	ServiceRepository repo = ServiceRepository.retrieveFrom(this.assembly);
    	ScriptEngine engine = repo.getService(ScriptEngine.class);
    	return new ScriptExpression<T>(engine);
    }
}
